A. Objectives Biomedical research in intellectual and developmental disabilities (IDD) continues to expand and involve new technologies and approaches. These technologies, for example, with high throughput instruments provide very large amounts of data. Bioinformatics support, including preprocessing these data for the IDDRC, is provided through its Genomics/Proteomics, Imaging and Neuroimaging Cores. The role of the Biostatistics and Informatics Core (BIC) is to collaborate with investigators in designing studies to make optimal use of today's capabilities of obtaining immense amounts of information and providing the inferential statistical analyses of the post-processed data in order to support the translation of the findings from these studies to clinical research. Our challenge is to help investigators pare down or obtain information by creatively adapting or designing studies and analyzing the clinical research study data that will either confirm the laboratory or biomarker findings or refute them. IDD clinical research studies, especially in pediatric populations, present design challenges, such as appropriate controls or control interventions, availability of only small sample sizes (especially in rare IDDs in children) that cannot be assessed too many times, and numerous sources of potential biases, as well as combining the research questions from several disciplines, providing interdisciplinary support. The BIC provides unique input in design, data collection approaches, data analyses and interpretation to implement strong design and complete, unbiased data. The specific objectives of the Biostatistics and Informatics Core are: Design of research studies with (1) review of aims and hypotheses and definition of key variables as well as design features, such as converting a traditional clinical trial design to an adaptive clinical trial design, and defining sample sizes which may be conditional; (2) development of statistical analysis plans using state-of-the-art methodologies; and (3) assessment of any obstacles of potential bias and feasibility and suggesting creative solutions to these less obvious considerations. Informatics support of study implementation and conduct including (1) assistance with choice of database platform and provision of database training and database design; (2) development of web-based electronic case report forms (eCRFs) for quick and efficient data capture, including tools to detect/correct errors; and (3) development of computerized approaches to monitoring study quality and progress. Statistical analyses and results dissemination including (1) data visualization and analyses; (2) data summaries for safety monitoring reports of ongoing clinical studies requiring data and safety monitoring; (3) data analyses using the most current statistical methods; and (4) interpretation of results for manuscripts and presentations. Methods/applications development The BIC has a particular focus on small sample methods and on grouped (clustered) data, and engages in methods development in these areas to enhance the support of IDDRC investigators. In order to accomplish these objectives, the BIC works in close collaboration with the other IDDRC cores to assure uniformity and comprehensiveness of approaches, interpreting data correctly for wider application in IDD.